Abstract: A refrigeration cycle or heat pump employing an electrochemical compressor. The cycle uses a working fluid at least one component of which is electrochemically active. Another component of the working fluid is condensable. In one embodiment, the electrochemically active component is hydrogen and the condensable component is water. The electrochemical compressor raises the pressure of the working fluid and delivers it to a condenser where the condensable component is precipitated by heat exchange with a sink fluid. The working fluid is then reduced in pressure in a thermal expansion valve. Subsequently, the low pressure working fluid is delivered to an evaporator where the condensed phase of the working fluid is boiled by heat exchange with a source fluid. The evaporator effluent working fluid may be partially in the gas phase and partially in the liquid phase when it is returned from the evaporator to the electrochemical compressor.